Pathogens
3 Minutes
Pathogens and harmful microorganisms for students: learn how diseases spread, their symptoms, and prevention. A science lesson in English.
- What pathogens are, plus the causes and symptoms of TB and cholera
- Influenza cold symptoms, and rabies transmission and prevention
- Malaria transmission by mosquitoes, symptoms, and antimalarial drugs
What this lesson teaches
Pathogens are harmful microorganisms that enter the human body and cause diseases. They can enter our systems through the food we eat, the water we drink, or the air we breathe.
Bacterial diseases
- Tuberculosis, or TB, is caused by the bacterium Mycobacterium tuberculosis and spreads between people through the air.
- Tuberculosis symptoms include a persistent cough, sudden weight loss, and shortness of breath, but getting the BCG vaccine protects against it.
- Cholera is caused by the bacterium Vibrio cholerae, which spreads mostly through flies as well as through contaminated food and water.
- Cholera causes severe dehydration, vomiting, and diarrhea, and it can be prevented by maintaining personal hygiene and taking the anti-cholera vaccine.
Viral diseases
- The common cold is caused by the influenza virus, which spreads through the air and produces a cough and a runny nose.
- People can avoid catching the common cold by keeping their distance from anyone who is already sick.
- Rabies is a deadly viral infection caused by Rhabdoviridae, which kills nearly 50,000 people every year.
- Rabies is transmitted through bites from infected dogs, cats, or bats, leading to fever, hallucinations where a person imagines things that are not there, and paralysis that prevents hands and legs from moving.
- People can protect themselves from rabies and survive the infection by receiving the anti-rabies vaccine.
Malaria from protozoa
Malaria is a deadly disease caused by a protozoan called Plasmodium. It spreads to humans when they are bitten by female Anopheles mosquitoes. An infected person experiences severe symptoms, including a high fever, nausea, and vomiting. Patients can recover from malaria by taking antimalarial drugs such as quinine and chloroquine, while protecting oneself from mosquito bites is the main way to prevent getting infected.
Protection and other hosts
Harmful microorganisms do not only target humans, as some pathogens also cause diseases in plants and animals. While microorganisms provide useful benefits in agriculture, industries, medicine, and daily life, pathogenic varieties require medical defenses such as vaccines and antimalarial drugs. Practicing personal hygiene, keeping away from sick individuals, and avoiding insect bites remain essential steps for stopping the spread of these illnesses.